Coding & Algorithms Interview Questions
Practice 3,469 real Coding & Algorithms interview questions for 2026. Covers companies like Meta, Amazon, Google, Uber, and Microsoft. Real questions from actual interviews with detailed solutions — ideal for focused interview preparation. Coding & Algorithms interview questions are the single most common technical gate for software engineering roles and are used to evaluate problem framing, algorithm selection, complexity trade-offs, correctness, edge-case reasoning, and clear communication under time pressure. Expect this category to appear in early technical screens and repeatedly across onsite loops at companies that weight it heavily (notably Meta, Google, and Amazon). Interviews will test arrays and strings, trees and graphs, dynamic programming, hashing and two‑pointer techniques, and the candidate’s ability to test and optimize code in a shared editor. Prepare with timed mock interviews, practice in the same editor you’ll use live, and build a progressive schedule that moves from fundamentals to medium/hard problems; typical candidates invest several weeks to a few months of focused practice depending on seniority and target company.
"I got asked a hardcore MCM DP question and I saw it on PracHub as well. Solved that question in 5 minutes. Without PracHub I doubt I could solve it in 5 hours. Though somehow didn't get hired, perhaps I guess I solved it too fast? /s"
"Believe me i'm a student here jn US. Recently interviewed for MSFT. They asked me exact question from PracHub. I saw it the night before and ignored it cause why waste time on random sites. I legit wanna go back and redo this whole thing if I had chance. Not saying will work for everyone but there is certainly some merit to that website. And i'm gonna use it in future prep from now on like lc tagged"
"10 years of experience but never worked at a top company. PracHub's senior-level questions helped me break into FAANG at 35. Age is just a number."
"I was skeptical about the 'real questions' claim, so I put it to the test. I searched for the exact question I got grilled on at my last Meta onsite... and it was right there. Word for word."
"Got a Google recruiter call on Monday, interview on Friday. Crammed PracHub for 4 days. Passed every round. This platform is a miracle worker."
"I've used LC, Glassdoor, and random Discords. Nothing comes close to the accuracy here. The questions are actually current — that's what got me. Felt like I had a cheat sheet during the interview."
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"PracHub Premium for one month cost me the price of two coffees a week. It landed me a $280K+ starting offer."
"Literally just signed a $600k offer. I only had 2 weeks to prep, so I focused entirely on the company-tagged lists here. If you're targeting L5+, don't overthink it."
"Coaches and bootcamp prep courses cost around $200-300 but PracHub Premium is actually less than a Netflix subscription. And it landed me a $178K offer."
"I honestly don't know how you guys gather so many real interview questions. It's almost scary. I walked into my Amazon loop and recognized 3 out of 4 problems from your database."
"Discovered PracHub 10 days before my interview. By day 5, I stopped being nervous. By interview day, I was actually excited to show what I knew."
"I recently cleared Uber interviews (strong hire in the design round) and all the questions were present in prachub."
"The search is what sold me. I typed in a really niche DP problem I got asked last year and it actually came up, full breakdown and everything. These guys are clearly updating it constantly."
Find the Most Frequent Character with a Tie-Breaker
Find the Most Frequent Character with a Tie-Breaker Implement most_frequent_character(text). text is a non-empty string of lowercase English letters. ...
Solve SQL and Python coding tasks
You are given a small library system with the following relational schema and several Python data-processing tasks. Answer the SQL questions and imple...
Solve Three Coding Interview Problems
The interview included three coding tasks: 1. Common ancestor in an N-ary tree You are given the root of an N-ary tree and two target nodes. Dete...
Implement local maxima, bagging, and k-means
This set of tasks evaluates algorithmic problem-solving and implementation skills across array processing (local maxima), ensemble methods (bagging cl...
Implement Price-Time Order Matching
This question evaluates understanding of limit-order book mechanics, priority-based matching, stateful stream processing, and data-structure managemen...
Implement Spreadsheet Cell Updates
This question evaluates skills in data structures, expression parsing, dependency graph management, incremental evaluation, and cycle detection for ma...
Solve four design-leaning coding problems
You are given four independent interview-style coding tasks. For each task, implement the requested function/class with clear inputs/outputs and reaso...
Return all valid word-break sentences
Given a string s and a dictionary of strings wordDict, insert spaces into s to form a sentence such that every token is in wordDict. Return all possib...
Maximize distinct values after unique ± offsets
This question evaluates combinatorial reasoning and algorithmic optimization skills, focusing on transforming arrays under distinct integer-offset con...
Select words to maximize unique characters
Problem You are given an array of strings words. You may choose any subset of these strings and concatenate the chosen strings in any order. Your goal...
Maximum Path Sum in an Indexed Binary Tree
Maximum Path Sum in an Indexed Binary Tree A nonempty binary tree is represented without custom node objects. values[i] is the value of node i. childr...
Maximize correct guesses in a hat line puzzle
This question evaluates logical reasoning about information constraints, group strategy design, and combinatorial encoding in the Coding & Algorithms ...
Calculate Days Between Arbitrary Gregorian Dates
Calculate the absolute number of days between arbitrary valid Gregorian dates without enumerating each day or relying on a limited date library. Accou...
Sample uniformly from a circle’s area
How would you generate a point (x, y) uniformly at random from the area of a circle of radius R centered at the origin? - Explain why naive choices (e...
The Celebrity Problem
The Celebrity Problem At a party there are n people, labeled 0 to n - 1. Among them there may be exactly one celebrity — a person who satisfies both o...
Simulate Threshold Infection Efficiently
Simulate Threshold Infection Efficiently You are given an m x n grid, a set of initially infected cells, and an integer threshold k. Time advances in ...
Spreading Contagion on a Grid
This question tests graph traversal and multi-source BFS on a 2D grid, evaluating a candidate's ability to model simultaneous state propagation across...
Schedule Non-Overlapping Meetings Efficiently
This question evaluates understanding of interval scheduling and overlap detection, proficiency in selecting efficient data structures for dynamic ord...
Implement a Unique Lines Command
This question evaluates mastery of file I/O, streaming algorithms, stateful line processing, and memory-efficient handling of large inputs, situating ...
Traverse a path and print directory tree
This question evaluates proficiency with filesystem I/O, path validation, directory traversal, recursion and error handling in Node.js, plus the abili...